Search PubMed⌕ Search

Biomedical subjects

H Ono

Publications and source records attributed to H Ono.

At least 451 records · Page 25Linked to original sources
PubMed1989

Acquired renal cysts in five-sixths nephrectomized rats: the roles of oxalate deposits in renal tubules and a renotropic factor.

The present study was undertaken to see if the oxalate deposits seen in renal tubules are a causative factor in the development of acquired renal cysts in chronic renal failure. Thirty 5/6 nephrectomized rats had free access to water containing 8 mg/ml of vitamin C (oxalate precursor) and 20 5/6 nephrectomized rats were given tap water without vitamin C. Oxalate deposits were found on microscopy in the renal tubules of vitamin C-treated rats in the 11th and 12th postnephrectomy months; however, acquired renal cysts were noted far in advance of the appearance of oxalate crystals. It has been suggested that the tubular dilatation seen in 5/6 nephrectomized rats is caused by an abrupt decrease in the functioning renal mass, leading to the production of a so-called 'renotropic factor'. However, oxalate deposits and renal tubular dilatation in oxalate-treated 5/6 nephrectomized rats preceded the renal tubular dilatation of untreated partially nephrectomized rats. In addition, these histological changes in the kidney were also seen in healthy rats which were given oxalate orally and subcutaneously. The present study suggested that the pathogenesis of acquired renal cysts is multifactorial. Renotropic factor may play an important role leading to nephron hyperplasia, but oxalate deposits in the renal tubules seem to be an important factor in the formation of these cysts.

Animals↗
PubMed1989

Effect of vitamin C supplementation on renal oxalate deposits in five-sixths nephrectomized rats.

We have previously reported that hyperoxalemia can be aggravated by vitamin C supplementation in regular hemodialysis patients. The present study was undertaken to examine the validity of this observation in an experimental setting. Fifty five-sixths nephrectomized rats were divided into two groups: 30 rats were allowed free access to water containing 8 mg/ml of vitamin C (100-160 mg/100 g/24 h) and the remainder given tap water without vitamin C. The serum creatinine increased and the Hct decreased gradually; however, there was no difference between the two groups. Plasma vitamin C, oxalate and urinary oxalate levels were higher in the vitamin -treated group than the nontreated rats. Histological examination revealed glomerular and interstitial fibrosis and round cell infiltration as well as tubular cyst formation. Oxalate deposits in renal tubules were found only in vitamin C-treated rats with advanced renal failure. Nontreated animals with equally advanced renal impairment showed no oxalate deposits. These results confirm our previous clinical findings that vitamin C supplementation aggravates the secondary oxalosis of chronic renal failure.

Animals↗
PubMed1989

Enhancement of spinal monosynaptic reflexes with phenylethylamine and related drugs through descending noradrenergic neurons.

The effects of phenylethylamine (PEA) and related drugs, such as methamphetamine, phenelzine, methylphenidate, nomifensine and mazindol on the spinal monosynaptic reflex (MSR) were investigated in rats treated with 6-hydroxydopamine (6-OHDA) or 5,6-dihydroxytryptamine (5,6-DHT). PEA (1 x 10(-5) mol/kg, i.v.) increased the amplitude of MSR in control rats, but decreased the amplitude in rats treated with 6-OHDA. Although PEA-related drugs increased the amplitude of MSR, they did not change the MSR amplitude in 6-OHDA-treated rats. In 5,6-DHT-treated rats, PEA-related drugs increased the amplitude of MSR, whereas PEA produced a decrease. These results support our previous suggestion that the enhancement of MSR by these drugs might be mediated through release of noradrenaline or inhibition of noradrenaline uptake at the noradrenergic synapses.

5,6-Dihydroxytryptamine↗
PubMed1989

Structure-activity relationships of phenylethylamine analogs in their serotonergic depressant effects on the spinal monosynaptic reflex in rats.

The effects of 2-phenylethylamine (PEA) and related compounds on the spinal monosynaptic reflex (MSR) were examined using C1-spinalized rats. At low doses, PEA, S(+)-amphetamine, S(+)-methamphetamine and phentermine increased the amplitude of the MSR, whereas high doses of these drugs reduced it. p-Substituted PEA analogs (p-C1-PEA, p-methoxy-PEA and (+/-)-p-C1-amphetamine) only reduced the MSR. Low doses of PEA-related rigid compounds, R(+)-2-aminotetralin, (+/-)-N-methyl-2-aminotetralin and (+/-)-N,N-dimethyl-2-aminotetralin only reduced the MSR. S(-)-2-Aminotetralin did not affect the MSR. Depressions of MSR produced by PEA, S(+)-methamphetamine and R(+)-2-aminotetralin were antagonized by ketanserin and haloperidol which have 5-hydroxytryptamine (5-HT) antagonistic activity, and the MSR depression caused by S(+)-methamphetamine but not PEA and R(+)-2-aminotetralin was abolished by intracisternal 5,6-dihydroxytryptamine treatment or chronic spinal transection. These results suggest that PEA-related compounds cause MSR depression by direct and indirect 5-HT agonistic mechanisms, and support the proposal that the PEA moiety which exists in R(+)-2-aminotetralin is important for the direct 5-HT agonistic activity of some hallucinogens.

Animals↗
PubMed1989

Influence of Bay k 8644 on aequorin-loaded human platelets.

In aequorin-loaded human platelets, Bay k 8644 (1-100 microM) had no effect on the resting level of cytoplasmic Ca2+ and did not induce aggregation by itself. Though the rise of cytoplasmic Ca2+ and platelet aggregation induced by thrombin (0.1 U/ml) also was not inhibited by 1-10 microM of Bay k 8644, at concentration of 3-10 microM, it dose-dependently reduced those induced by collagen (5 micrograms/ml). The present study shows that human platelets do not have dihydropyridine sensitive Ca channels.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1989

Effects of sera, hormones and granulosa cells added to culture medium for in-vitro maturation, fertilization, cleavage and development of bovine oocytes.

Sera (fetal calf serum: FCS; and oestrous cow serum: ECS), hormones (2.5 FSH micrograms/ml + 5 micrograms LH/ml + 1 microgram oestradiol/ml) and granulosa cells (5 x 10(6)/ml) were added to culture medium to determine the frequencies of in-vitro maturation, fertilization, cleavage (2- to 8-cell) and development into blastocysts of bovine follicular oocytes. The maturation rates after 24 h in culture were not significantly different among the three factors tested (56-72%). The fertilization rates were significantly affected by serum type and the addition of granulosa cells. FCS gave significantly higher rates of fertilization (57-71%) than did ECS (34-52%), but the proportions of polyspermic fertilization were significantly higher in the former (8-19%) than in the latter (2-3%). The addition of hormones did not affect fertilization, cleavage and development. Neither type of serum affected cleavage and development. The highest rates of blastocyst formation were obtained when granulosa cells alone were added (FCS, 17%; ECS, 16%). The cell numbers of the blastocysts obtained were 100-150, similar to those of blastocysts developed in vivo. Transfer of 6 blastocysts to 3 cows resulted in 1 pregnancy. The present results indicate that the co-culture with granulosa cells is the most important factor for in-vitro fertilization to development into blastocysts of bovine oocytes matured in vitro.

Animals↗
PubMed1989

The roles of convergence and apparent distance in depth constancy with motion parallax.

The question of whether motion parallax is calibrated by convergence or by apparent distance for depth perception was addressed in three experiments. In Experiment 1, a random dot parallactic display was viewed monocularly at a distance of 80 cm, and the convergence angles were set for distances of 40, 60, and 80 cm. Averaged apparent depth was not different across conditions. In Experiment 2, a display consisting of one surface showing dollar bills and one surface showing random dots was viewed monocularly at a distance of 80 cm. It was presented at two different apparent distances, which were manipulated by varying the size of the dollar bills. In one condition, normally sized dollar bills were presented, and in another condition, the size was reduced by 30%. The averaged apparent depth associated with the small-bill display was larger than the depth associated with the normally sized bill display. In Experiment 3, a random dot display was viewed monocularly at 120 cm. In the primary condition, the random dot display was viewed with an induction screen at 80 cm, and it was moved from side to side such that it appeared stationary and close to the plane of the induction screen. In a comparison condition, the display was viewed without the induction screen and was moving from side to side at 120 cm. In another comparison condition, the display was again viewed without the induction screen but was stationary at 120 cm. Observers adjusted the extent of motion parallax so that apparent depth was 1 cm. The mean extent of parallax was larger in the primary conditio.(ABSTRACT TRUNCATED AT 250 WORDS)

Accommodation, Ocular↗
PubMed1989

Lactivicin, a naturally occurring non-beta-lactam antibiotic having beta-lactam-like action: biological activities and mode of action.

Lactivicin is moderately active against a wide range of Gram-negative bacteria and highly active against Gram-positive bacteria. It shows various biological activities commonly observed with beta-lactam antibiotics, such as higher activity against beta-lactam hypersensitive mutants than against their parents, sensitivity to beta-lactamases, inhibitory activity against beta-lactamases and ability to induce beta-lactamase activity. The primary lethal target of lactivicin in Escherichia coli is highly likely to be penicillin-binding protein (PBP) 1; lactivicin strongly lysed E. coli cells with induction of spheroplasts at its MIC, and showed high affinity for PBPs 1A and 1B. At concentrations above x 5 MIC, however, lactivicin dominantly exhibited secondary antibacterial action possibly owing to inhibition of crucial SH proteins engaged in the fundamental membrane functions. In contrast, against Bacillus subtilis, lactivicin showed the typical beta-lactam action under a wide range of concentrations. It showed high affinity for PBPs 1, 2 and 4, the possible lethal targets of beta-lactam antibiotics in this organism. In conclusion, lactivicin is the first non-beta-lactam antibiotic showing beta-lactam action through binding to PBPs.

Anti-Bacterial Agents↗
PubMed1989

[Hyperamylasemia in endometrial adenocarcinoma].

Two patients suffering from endometrial adenocarcinoma (endometrial type) showed hyperamylasemia. The elevated level of amylase in the serum dropped to the normal range after operation in case 1. Case 2 had a recurrent tumor and continued to have a high amylase concentration in the blood. Isozyme analysis of serum-amylase showed predominant patterns of the salivary type. Tumor homogenates contained only salivary type amylase. Immunohistochemical staining revealed localizations of amylase in these tumor tissues. So it was clear that the production and secretion of salivary type amylase caused hyperamylasemia. Further study was done immunohistochemically to find the incidence of amylase-productive endometrial adenocarcinoma (endometrial type). It was shown that 56% of these tumors had amylase in neoplastic cells. Well differentiated adenocarcinoma showed a high frequency of amylase-positive findings. It was suggested that amylase measurement would provide useful information in checking the recurrence and in monitoring the therapeutic effects of endometrial adenocarcinoma.

Adenocarcinoma↗
PubMed1989

[Recovery of fluoride orally on the acid-etched tooth surface].

There are many reports concerning the recovery phenomenon of acid-etched enamel surfaces of teeth. Many studies of surface hardness, acid resistant properties, radiolucency, and surface morphology suggest that orally the acid-etched enamel reverts to a state nearly similar to that of the intact enamel before the acid etching. This study was conducted in order to verify the existence of the recovery phenomenon of fluoride on acid-etched enamel, because the surface layer of a high fluoride concentration is removed from the surface enamel by the acid etching. The deciduous upper central incisors of both sides were etched with phosphoric acid. The fluoride content of one incisor was measured immediately after the etching and that of the opposite incisor was also measured in vivo after 4 weeks, during which period no special fluoride was used. The fluoride content of the tooth surface in the mouth after 4 weeks significantly increased by about 50 ppm, when compared to that immediately after the acid etching. No significant relationship was found between the fluoride increase and the fluoride concentration of the patients' saliva and drinking water which were the probable supply sources of fluoride for the teeth. No relationship was found between the fluoride increase and the number of second deciduous molars with defects or fillings, which was counted as a measure of the patient's susceptibility to caries.

Acid Etching, Dental↗
PubMed1989

[Two cases of temporomandibular arthrosis of young children].

Two cases of temporomandibular arthrosis were reported. Case 1 was a 6 years 4 months old female with pain in her left mandibular region in moving her jaw. Opening of the mouth by herself was slightly limited. Clicking noise was seen and felt from both of her temporomandibular joints. She was in the dental developmental stage IIA by Hellman, and had deep overbite (5mm). Roentogenographic examination revealed a bony defect on her left condylar head. Treatment was performed with an activator. Pain was not felt and the mandibular opening recovered after 2 weeks of treatment. Roetogenographs showed no bony defect on her left condylar head after 5 months of treatment. Case 2 was a 3 years 2 months old male with clicking noise from both of his temporomandibular joints. There was no pain and no limitation of his mouth opening. He was in the dental developmental stage IIA by Hellman, and had large overjet (8mm). He has thumb sucking habit since the age of one year. He is now under regular observation.

Activator Appliances↗
PubMed1989

[The effect of the elastase on aminonucleoside nephrosis].

In this paper, we studied the effect of elastase on aminonucleoside (AN) nephrosis which is considered a model of focal glomerular sclerosis (FGS). Elastase is an enzyme which disintegrates elastin, discovered by Balo, and used in the treatment of arteriosclerosis and hyperlipidemia. It has also been known to improve metabolism of acid mucopolysaccharides, so, this study focused on metabolic improvement. Three groups of male Sprague-Dawley rats were studied and observed at regular intervals; 30, 60, 90 days. The ANE group (AN + elastase) was administered one shot of AN (10 mg/100 g B.W.) during the test interval, while elastase (5 mg/kg B.W.) was injected 5 days/week for the entire test interval. The AN group was administered one shot of AN only. The third group was a control (C). The following results were observed: (1) Focal segmental hyalinosis and sclerosis (FSHS); ANE group was weaker than AN group. (2) Other significant qualifying glomerular changes (vacuolar change and hyaline droplets of the epithelial cells, adhesion, and foam cells); ANE group was weaker than AN group. (3) Anion loss in GBM was shown by a lack of colloidal iron staining under light microscopy, and by a lack of PEI particles under electron microscopy; there was significantly less anion loss with ANE group, than with AN group. The findings suggest that elastase has an affect on the metabolism of acid mucopolysaccharide and collagen in sclerotic lesion, and may restrain the progress of amino-nucleoside nephrosis.

Animals↗
PubMed1989

Somatostatinoma of the rectum.

We report a case of a 29-yr-old man with a rectal carcinoid that metastasized to the liver, secreting somatostatin. The patient first presented with an abdominal mass and mild diabetes, and, subsequently, rectal tumor and hypersomatostatinemia. Microscopic examination of the rectal tumor showed characteristic features of carcinoid. Multiple liver metastases were recognized. The plasma level of somatostatin was remarkably high (2,839 pg/ml). Plasma gut glucagon and pancreatic polypeptide (PP) increased with progress of the disease. He died of hepatic failure 20 months after his first admission. Immunoperoxidase staining showed that rectal tumor cells contained somatostatin-like-immunoreactivity. Electron microscopy of tumor tissue showed neurosecretory (D-cell) granules. Somatostatin content of the rectal tumor was very high (5,629 pg/mg).

Adult↗
PubMed1989

[Pathomorphological studies on arterial cushion. 2. Aminonucleoside nephrotic rat].

The present study is an attempt to solve the problem of pathogenesis of focal glomerular sclerosis (FGS), especially in juxtamedullary cortex, we were investigated by measurement of luminal diameters of afferent arterioles (Aff), efferent arterioles (Eff) of numerous glomeruli, arterial cushion (AC), afferent arterioles (AC-aff) at a region of branching arteries from the interlobular arteries, using scanning electron micrographs of methyl methacrylate casts of intrarenal arteries of aminonucleoside nephrotic rats. As regards luminal diameters, Eff were nearly equal Aff in minor glomerular abnormalities (Minor). Nevertheless Eff of glomeruli with segmental sclerosis (FSHS) were smaller than Aff (t-test). AC with FSHS were smaller than ones of Minor, statistically (t-test). The results of these examination, the cushion may be important factor for the regulation of blood flow in sclerotic glomeruli.

Animals↗
PubMed1989

[The role of oxygen free radical and free radical scavenger in septic and hemorrhagic shock].

The roles of oxygen free radical (O2-), lipoperoxide (LPO) and free radical scavenger were clinically and experimentally studied in septic and hemorrhagic shock. The reduction of hepatic tissue blood flow (TBF) were equalized in two groups (40-55% of normal level) and rats were subdivided into 3 groups: untreated, normal saline (NS) continuous IV and superoxide dismutase: SOD + catalase (S/c) continuous IV as free radical scavenger. The change of TBF, destruction of mitochondrial structure and elevation of LPO were prevented by S/c in Et shock. No significant effect by S/c was observed in hemorrhagic shock. The neutrophil derived O2- was markedly elevated in Et shock animals as well as septic shock patients but no significant change was noted in hemorrhagic shock animals or non septic shock patient. SOD and catalase were effective for neutrophil derived O2- in septic shock whereas little beneficial effect was noted in hemorrhagic or non septic shock.

Animals↗
PubMed1989

[Chemical change of calcium hydroxide contained in root canal filling materials in serum].

In the previous report we showed the conversion of calcium hydroxide contained in root canal filling materials to calcium carbonate by means of 4 weeks of subcutaneous implantation in rats. The purpose of this study was to discover if this reaction would take place in vitro as a chemical reaction and also to find out the rate of the conversion. The alteration of three materials. Vitapex, Calvital, calcium hydroxide, when in serum, was checked and the alteration of the latter two, when in the air, was checked. The solubility of calcium hydroxide in serum or distilled water was also determined. The results showed that calcium hydroxide was neutralized to calcium carbonate after several weeks in the serum. The conversion in the air was much slower than that in the serum. This means that calcium hydroxide will not change while in storage and when it has no contact with the tissue fluid. Calcium hydroxide was dissolved in both the serum and distilled water, but calcium carbonate was not. This fact suggests that calcium hydroxide neutralized to calcium carbonate by serum will cause little or no chemical irritation.

Animals↗